Biocides are often used in the oil or gas field for remediation or prevention purposes. For example, biocides are often applied to reduce or “knockdown” the high numbers of bacteria in formulations that are pumped downhole in connection with fracturing (“fraccing”), reinjection or other oil or gas field operations.
While biocide compositions are available that provide adequate biocidal activity in downhole operations, further improvements in performance are desired. For example, a way of providing long lasting residual biocidal activity using smaller amounts of biocidal agent would be of considerable advantage. It would be especially advantageous if the biocidal agent is compatible with other components used in downhole operations, is relatively non-corrosive to metals, is capable of providing rapid microbiocidal activity promptly upon reaching the downhole regions, and is effective against a variety of aerobic and anaerobic bacterial species including sulfate-reducing species that produce hydrogen sulfide and resultant “souring” of the hole.